1. Field of the Invention
The present invention relates generally to retractable coverings for architectural openings and, more particularly, to safety operating cord systems for such a covering.
2. Description of the Relevant Art
Retractable coverings for various architectural opening such as windows, doorways, archways, and the like typically include a retractable barrier which might be a drapery, mini-blind, vertical blind or the like. Such retractable window coverings are typically operated with at least one pull cord system. The operating cord system can be used to extend or retract the covering across the architectural opening or to manipulate vanes utilized in the covering into various positions when the covering is extended. In either event, a pair of cords or a closed loop cord typically depend from one end of the covering for hand manipulation by an operator.
When the pull cord has two free ends, they are many times interconnected to form a closed loop to facilitate operation of the covering. Endless cords are also utilized. The closed loop or endless cords pose an inherent danger to young children and infants in that should the head of the child or infant become entangled in the operating cord, the child or infant can be inadvertently hung or otherwise badly injured.
To resolve the inherent danger presented by operating cords that have their ends interconnected to establish an endless loop, safety systems have been devised. For example, where two free ends of a operating cord are interconnected with a connector, some connectors have been designed to separate or disengage the connection of the free ends of the cord upon a particular force being applied to the cords. An example of such a system is shown in U.S. Pat. No. 5,518,057 issued May 21, 1996. The system disclosed in the patent utilizes a cap in which one end of the operating cord can be securely fixed and in which the opposite end of the operating cord can be releasably fixed such that when a separating force is provided between the two operating cords in effect increasing the separation between the cords, the releasable end of the operating cord is allowed to pass through an enlarged slot in the cap so that it is released from the cap thereby allowing the two cords to be separated so that even if a child or infant's head were caught between the two depending portions of the operating cord, it would not cause injury as the effective endless nature of the cord would have been eliminated.
Another example of a safety system is disclosed in U.S. Pat. No. 4,909,298 issued Mar. 20, 1990. In this system the connector at the free ends of an operating cord is designed to separate into two parts upon predetermined forces applied thereto such that each cord end remains connected to one part of the connector but the operating cord is thereby separated to avoid injury to a child whose head may have been caught in the cord.
It is also well known in the field of retractable coverings for architectural openings to provide clutch systems between the operating cords and tilt rods, control rods or roll bars used in the operation of the covering so that the tilt rod or the like can only be rotated under desired conditions. In a typical system, the operating cord is operatively engaged with a drive wheel which is coupled to the tilt rod with the clutch system so that neither the drive wheel nor the tilt rod will rotate unless an axial pulling force is applied to one depending portion of the operating cord or another. Such an arrangement, for example, prevents a window shade from coming unrolled due to the weight of the shade unless their is a desired manipulation of the operating cord.
Current art is devoid of a reliable system for preventing the above described injury to children or infants inasmuch as prior art systems are dependent upon a particular separating force being applied between the two depending portions of the operating cord, but if the operating cord is twisted, knotted or the like, the force may not release the operating cord from the connector and resultant injury to the child may occur.
To date, almost all of the attention directed to childproofing operating cords has been focused on the connector at the lower free end of the operating cord, but as mentioned previously, certain limitations are presented when trying to resolve the problem by focusing on the free ends of the cord and their interconnection with each other.
It is to overcome the shortcomings in the prior art and to provide a new and improved system for releasing a operating cord from its operative connection with the control mechanism of an architectural covering that the present invention has been developed.